Of this harbour is the Capo Caccia, with two stalactite grottos, the finest of which, the Grotta di Nettuno, is accessible only from the sea.
The cathedral, of the 12th century, has a carved portal and three apses decorated with small arches and pilasters, and contains a fine pulpit and episcopal throne in marble mosaic. Near it are two grottos 1 To the period after 335 belong numerous silver and bronze coins with the legend Caleno.
Amongst the best-known are the grottos of Adelsberg, the larger ones of Planina and the Kreuzberghohle near Laas.
At Syracuse also there are very extensive catacombs known as " the Grottos of St John."